1. Field of the Invention
This invention generally relates to the clutch plate and the retaining plate of a dampening disk assembly, which is used in a clutch of a motorized vehicle. More specifically, the present invention relates to the shape of the rectangular windows are formed such that they reduce wear and increase the life span of the plate.
2. Background Information
A clutch disk assembly or dampening disk assembly used for a clutch of a car has a clutch function of coupling and/or uncoupling a flywheel of the engine to the transmission shaft, and a dampening function of absorbing and dampening torsion vibrations transmitted from the flywheel. The clutch disk assembly basically includes a clutch disk, a pair of input plates, a hub and an elastic portion. The input plates are fixedly coupled to the clutch disk. The hub is disposed on the inner circumferential side of the input plate. The elastic portion elastically couples the hub and the input plates together for movement in a rotary direction. The elastic portion is disposed between the input plates and the hub, and is compressed in a rotary direction when the input plate rotates relatively against the hub. When the clutch disk assembly is coupled with the flywheel, a torque is inputted to the input plates of the clutch disk assembly from the flywheel. The torque is transmitted to the hub via the elastic portion, and then is outputted to a shaft extending from a transmission. When a torque fluctuation is input to the clutch disk assembly from an engine, a relative rotation is caused between the pair of input plates and the hub, and the elastic portion is compressed repeatedly in a circular direction.
In addition, the clutch disk assembly typically includes a friction mechanism. The friction mechanism is disposed between the input plates and the hub, and generates a friction resistance when the input plates rotate relatively against the hub. The friction mechanism includes basically a plurality of washers and urging portions.
In general, a clutch disk assembly or dampening disk assembly used in a clutch of a vehicle. The dampening disk assembly includes an input portion connected with a flywheel on an engine side, and a spline hub connected with a shaft extending from a transmission. The input portion and the spline hub are coupled in a circular direction by a dampening mechanism. The dampening mechanism includes a plurality of coil springs. The input portion includes a friction facing pressed by a flywheel and a pair of disk like plates. The spline hub includes a boss part in which the shaft from the transmission is inlayed, and a flange extending to an outer circumferential side of the boss part. Window holes are formed in the flange, and within each window hole is an elastic portion such as a coil spring. The two plates have rectangular windows (spring supporting part), which are formed by punching and cut and lift in an axial direction, at locations corresponding to the coil springs. These rectangular windows have convex shapes, which are formed by a drawing method. Both circular end parts of the rectangular windows touch both end parts of the coil springs, and operate as a connecting part for transmitting torque therebetween. In addition, the rectangular windows operate as spring casings to seat the coil springs and regulate the coil springs movements in both axial and radial directions.
The rectangular windows (tunnel-type) are formed in the plate main body by drawing, so as to be a convex shape continuing in a radial direction and having a large area which the coil spring touches. As a result, while the spring is compressed and rubs the rectangular window, the window experiences less abrasion.
Recently, the size of the coil spring seated in the rectangular window is getting larger, and both the size of a part of the rectangular window projecting in an axial direction from the plate main body and its cut and lift angle are getting larger.
The rectangular window which is formed at the clutch plate and retaining plate of the conventional clutch disk assembly mentioned above includes an axially supporting part and circular supporting part. The radially outside part of the axially supporting part supports the radially outside part of the coil spring. This radially outside supporting part has an arc like bent shape along an operating (compressing) orbit of the coil spring. When a torsion vibration is transmitted to the clutch disk assembly, the coil spring moves to the radially outside part by a centrifugal force and rubs the rectangular window. Consequently, the radially outside supporting part of the rectangular window is wholly abraded. When the thickness of both circular end corner part of the radially outside supporting part of the rectangular window gets small, the possibility that the corner part is cracked increases.
In view of the above, there exists a need for a dampening disk assembly with an improved plate or plates which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.